RESUMO
Cytokines are believed to be important in maintaining pregnancy and in the process of labour induction in humans. The aim of this study was to investigate the secretion of the cytokines interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-10, transforming growth factor-beta (TGF-beta) and tumour necrosis factor-alpha (TNF-alpha) in decidual tissue with or without labour. Decidual tissue was collected from 32 healthy women undergoing elective caesarean sections before the onset of labour (n=17) or after normal vaginal delivery (n=15). Mononuclear cells were analysed for cytokine secretion with ELISPOT. To validate the widely used method of tissue collected at caesarean sections and after vaginal deliveries as a representative of before and after labour, respectively, placenta biopsies were collected from 12 healthy women to study the expression of the prostaglandin pathway enzymes cyclooxygenase-2 (COX-2) and microsomal prostaglandin E(2) synthase (mPGES). Decidual mononuclear cells from term human pregnancy spontaneously secrete IFN-gamma, IL-4, IL-10, TGF-beta and TNF-alpha. No difference was seen in cytokine secretion with or without labour, indicating that decidual leukocytes are not the main cell population responsible for plausible cytokine regulation in the process of termination of pregnancy. Placental tissues obtained after vaginal delivery showed a higher mRNA expression of the prostaglandin regulating molecules COX-2 and mPGES than tissues from caesarean sections before the onset of labour, validating that the model can be used as a representative of the state before and after labour.